Photocatalytic hydrogen production on Pt-loaded TiO2 inverse opals

• TiO2 inverse opals and macroporous TiO2 were used in H2 production experiments.
• Inverse opals show higher rates due to slow photons.
• Polymer template influences the crystallinity and the performance of TiO2 samples.
• No evidence for faster electron transfer in TIOs during H2 photoproduction.
• Inverse opals are effective both on oxidation and reduction photocatalytic reactions.

TiO2 inverse opals present increased photocatalytic production of H2. TiO2 inverse opals with different pore size and TiO2 macroporous structures with disordered arrangement of the pores have been tested in the photocatalytic production of hydrogen in aqueous solution with a formate buffer as hole scavenger. TiO2 inverse opals belong to the family of metamaterials and exhibit unique catalytic properties arising from their peculiar interaction with light. To discriminate the effects of slow photons the hydrogen photoproduction experiments were carried out at two different wavelengths, at 365 nm where the effect of slow photons is maximized, and at 254 nm where it is negligible. The resulting hydrogen production rates suggest a strong effect of the slow light and of the polymer template used in the synthesis of the TiO2 powders. The chemical properties of the polymeric sacrificial template determine the crystalline phase of the sample and as a consequence affect the catalytic performances of the resulting TiO2 structures.

Figure optionsDownload as PowerPoint slide